Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D295/00—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms
  • C07D295/04—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with substituted hydrocarbon radicals attached to ring nitrogen atoms
  • C07D295/12—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with substituted hydrocarbon radicals attached to ring nitrogen atoms substituted by singly or doubly bound nitrogen atoms
  • C07D295/125—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with substituted hydrocarbon radicals attached to ring nitrogen atoms substituted by singly or doubly bound nitrogen atoms with the ring nitrogen atoms and the substituent nitrogen atoms attached to the same carbon chain, which is not interrupted by carbocyclic rings
  • C07D295/13—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with substituted hydrocarbon radicals attached to ring nitrogen atoms substituted by singly or doubly bound nitrogen atoms with the ring nitrogen atoms and the substituent nitrogen atoms attached to the same carbon chain, which is not interrupted by carbocyclic rings to an acyclic saturated chain
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C275/00—Derivatives of urea, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
  • C07C275/04—Derivatives of urea, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups having nitrogen atoms of urea groups bound to acyclic carbon atoms
  • C07C275/06—Derivatives of urea, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups having nitrogen atoms of urea groups bound to acyclic carbon atoms of an acyclic and saturated carbon skeleton
  • C07C275/14—Derivatives of urea, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups having nitrogen atoms of urea groups bound to acyclic carbon atoms of an acyclic and saturated carbon skeleton being further substituted by nitrogen atoms not being part of nitro or nitroso groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C275/00—Derivatives of urea, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
  • C07C275/04—Derivatives of urea, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups having nitrogen atoms of urea groups bound to acyclic carbon atoms
  • C07C275/20—Derivatives of urea, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups having nitrogen atoms of urea groups bound to acyclic carbon atoms of an unsaturated carbon skeleton
  • C07C275/24—Derivatives of urea, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups having nitrogen atoms of urea groups bound to acyclic carbon atoms of an unsaturated carbon skeleton containing six-membered aromatic rings
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G12/00—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
  • C08G12/02—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes
  • C08G12/04—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with acyclic or carbocyclic compounds
  • C08G12/043—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with acyclic or carbocyclic compounds with at least two compounds covered by more than one of the groups C08G12/06 - C08G12/24
  • C08G12/046—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with acyclic or carbocyclic compounds with at least two compounds covered by more than one of the groups C08G12/06 - C08G12/24 one being urea or thiourea
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G14/00—Condensation polymers of aldehydes or ketones with two or more other monomers covered by at least two of the groups C08G8/00 - C08G12/00
  • C08G14/02—Condensation polymers of aldehydes or ketones with two or more other monomers covered by at least two of the groups C08G8/00 - C08G12/00 of aldehydes
  • C08G14/04—Condensation polymers of aldehydes or ketones with two or more other monomers covered by at least two of the groups C08G8/00 - C08G12/00 of aldehydes with phenols
  • C08G14/06—Condensation polymers of aldehydes or ketones with two or more other monomers covered by at least two of the groups C08G8/00 - C08G12/00 of aldehydes with phenols and monomers containing hydrogen attached to nitrogen
  • C08G14/08—Ureas; Thioureas
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
  • C08G59/4007—Curing agents not provided for by the groups C08G59/42 - C08G59/66
  • C08G59/4014—Nitrogen containing compounds
  • C08G59/4021—Ureas; Thioureas; Guanidines; Dicyandiamides
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
  • C08G59/62—Alcohols or phenols
  • C08G59/621—Phenols
  • C08G59/623—Aminophenols

Definitions

• This invention relates to novel compounds useful as epoxy curing agents, to a method for making these new compounds, to a novel method of curing epoxy resins, and to novel cured epoxy resins.
• a new class of epoxy curing agents has been discovered that utilizes the structure of urea-formaldehyde and also the structure of phenol-modified urea-formaldehyde as the center of a polyamine molecule.
• the amine groups are arranged around the urea-formaldehyde center in a radial fashion. This may be represented as :
• R 1 , R 2 , R 3 , and R 4 as defined below.
• This structure has a low amount of steric hindrance; that is, the structure of the molecule allows the most space between its components. This provides easy access for an epoxy molecule to react with these widely spaced amine groups.
• the structures of these new compounds give a high degree of cross linking when reacted with epoxy resins and, therefore, contributes to the toughness and strength of the cured amine-epoxy resin.
• Another advantage of incorporation of the urea-formaldehyde structure in the polyamine curing agent is that the curing agent is water-white in color, and so the subsequently cured amine-epoxy resin can be water-white.
• Urea-formaldehyde resins themselves are intrinsically colorless and resist becoming yellowish, and this same resistance to yellowing can be incorporated in the urea-formaldehyde polyamine structure.
• the phenol-modified urea-formaldehyde resins have some yellowness, but are quite light. Both the urea-formaldehyde polyamines and the phenol-modified urea-formaldehyde polyamines can be low in cost, because urea, formaldehyde, and phenol are low-cost raw materials, and so are many of the polyamines.
• urea-formaldehyde polyamine curing agents Success in manufacturing these urea-formaldehyde polyamine curing agents depends, in part, on employing a process of urea-formaldehyde synthesis that produces largely monomeric urea-formaldehyde molecules.
• One successful method of making urea-formaldehyde monomers is to react urea and paraformaldehyde in a lowmolecular-weight alcohol, such as methanol at a ratio of urea molecules to formaldehyde molecules of one to four. This results in the following general structure:
• R is a methyl, ethyl, propyl, or butyl radical.
• R 5 is a lower alkyl radical, having one to four carbon atoms. This ease of splitting of these ether groups is somewhat surprising, because I had earlier found that the corresponding ether groups in a melamine formaldehyde resin are not split, under the same conditions.
• X 1 may be generalized as
• R 2 and R 3 are both H.
• amine (o) either R 2 or R 3 , but not both, is C 18 H 35 and the other one is again H.
• X 1 is as defined above, while
• X 2 may either be identical to X 1 or may be
• R 4 is H or an alkyl radical with one to nine carbon atoms.
• amine curing agents on the market that are made from phenol, formalin (a water solution of formaldehyde) and a polyamine. These have no relationship to the urea-formaldehyde polyamines of the present invention because they are made by a different chemical route, and have vastly different properties. The manufacture of these phenol-formaldehyde amines is illustrated by Product Data Sheet 22-E-370-2-6 published by Veba-Chemie AG of Germany, which describes the reacting of phenol and 36% formalin using a basic catalyst.
• the polyamine is added to this water solution of the phenol-formaldehyde resin, and subsequently the water is driven off, resulting in a yellow viscous liquid.
• this resin is in no way related to the urea-formaldehyde polyamines of this invention, for no ether groups are formed in the water solution of phenol and formaldehyde under the above-stated basic conditions.
• the urea-formaldehyde monomers are made in an alcohol medium.
• the urea, paraformaldehyde (a solid form or polymer of formaldehyde having typically 91% formadehyde content), and an alcohol, such as methanol, are first subjected to basic conditions under low heat such as 50°C.
• This brief alkaline reaction causes the paraformaldehyde to dissolve. Then the reaction is made strongly acidic, e.g., a pH of 2; at this time an exotherm takes place, as a result of the formation of ether groups, for ethers of urea-formaldehyde are only formed under acid conditions. The reaction is held at 70-80°C. for a time in the order of one hour, to insure good ether formation. The monomer reaction is then finished by bringing the pH to 7.0. There may be small amounts of methylol groups in these urea-formaldehyde monomers. These methylol groups react with the polyamine in the same manner as the ethers react.
• ether groups in the urea-formaldehyde resin can be followed by infrared spectrophotometry analysis.
• a sample of the reaction is scanned in an infrared spectroscopy instrument.
• the ether groups in urea-formaldehyde are shown by an infrared peak at 9.3 microns (1075 cm -1 ). See the book An Infrared Spectroscopy Atlas for the Coatings Industry, 1980, Federation of Societies for Coating Technology, page 33. This 9.3 micron peak develops soon after acidic conditions are made.
• the final urea-formaldehyde monomer has a very large 9.3 micron ether peak at the end of the reaction.
• the progress of the reaction of the urea-formaldehyde monomer with the polyamine can be followed by noting that the ether peak is destroyed very soon after the urea-formaldehyde monomer is added to the polyamine.
• the finished reaction product has no trace of this 9.3 micron peak.
• the mixing of the urea-formaldehyde monomer into the polyamine is generally done at low temperature, such as 25°C. An exotherm takes place during the mixing which raises the temperature some 30°C. Then the alcohol and water of reaction are distilled off giving typically a water white, low viscosity, transparent liquid with remarkably good epoxy curing properties.
• Example 1 Urea-Formaldehyde Monomer in Methanol In a three liter glass flask fitted with a stainless steel paddle stirrer, thermometer, a pH electrode and a reflux condenser, is charged:
• the cooled urea-formaldehyde solution had suspended Na 2 SO 4 in it, which was filtered out leaving a water-white, transparent, low-viscosity liquid containing about 55% non-volatile urea-formaldehyde monomer.
• Infrared analysis showed a strong peak at 9.3 microns, indicating ethers of methloyl groups.
• the cooled thiourea-formaldehyde solution had suspended Na 2 SO 4 in it, which was filtered out leaving a water-white, transparent low-viscosity liquid containing about 48% non-volatile thiourea-formaldehyde monomer.
• Example 3 Composite Urea-Nonyl-Phenol Formaldehyde Monomer In a 500 ml. glass flask fitted with a stainless steel paddle stirrer, thermometer, pH electrode, and reflux condenser, the following ingredients were added:
• Example 4 Composite Urea-Phenol Formaldehyde Monomer In a one liter glass flask fitted with a stainless steel paddle stirrer, thermometer, pH electrode and reflux condenser, the following ingredients were added:
• Example 5 Urea-Formaldehyde Monomer Reacted with an Aromatic Polyamine
• the urea-formaldehyde monomer of Example 1 in an amount of 85 grams (47.5 grams of non-volatiles, i.e., 1 equivalents), is reacted with 1 mole (304 grams) of du Pont BABA, having a composition, weight percent: p,p-methylene dianiline 3-10% 2,4-bis(p-aminobenzyl) aniline (triamine) 70-80% tetramine 10-80% higher amines 1
• the aromatic polyamine was heated and stirred in a flask to 100°C. and the urea-formaldehyde monomer was added over 20 min. time and the temperature had climbed to 125°C. Then 50 g. of benzyl alcohol was added to reduce the viscosity of this thick red brown liquid with a whitish crust on top. Methanol was distilled off during this time. Subsequently the whitish crust was dispersed in the red brown liquid and the crust dissolved into the main liquid giving a transparent viscous liquid at 150°C. This liquid solidified as a dark red-brown brittle solid at about 90°C., considerably higher than the starting polymethylene dianiline.
• urea-formaldehyde is abbreviated to UF, urea-formaldehyde monomer to UFM, and urea-phenol-substituted-formaldehyde to UPFM.
• These properties may be hardness, flexibility, chemical resistance, etc., obtaining either a maximum of one of these or the desired best overall aggregation of properties, for maximum results for one property does not necessarily mean maximum results for another property; so there may not be any one ratio at which the best results for all properties coincide.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Epoxy Resins (AREA)
• Phenolic Resins Or Amino Resins (AREA)

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• 1982
  • 1982-07-08 US US06/396,319 patent/US4490510A/en not_active Expired - Lifetime
• 1983
  • 1983-06-30 DE DE8383902586T patent/DE3379226D1/de not_active Expired
  • 1983-06-30 WO PCT/US1983/001027 patent/WO1984000376A1/en active IP Right Grant
  • 1983-06-30 EP EP83902586A patent/EP0113774B1/de not_active Expired
  • 1983-07-06 CA CA000431913A patent/CA1215065A/en not_active Expired

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